20 — 



with his head. This nest contained four eggs advanced in in- 

 cubation. 



The eastern or left bank of Swan Kiver, from the bridge to 

 its mouth, has a well-w^om trail made by fishermen. A nest 

 of the warbling vireo was noted on June 23 beside this path. 

 It was six feet from the ground, in a clump of syringa, and con- 

 tained three well-fledged young. This instance and the pre- 

 ceding one illustrate a common tendency of several familiar 

 species to establish their homes along paths and trails in gen- 

 eral use, a trait mentioned in our notes concerning the nidifi- 

 cation of the olive-backed thrush. 



The woods across the road from the laboratory grounds fur- 

 nished us another note for June 26. A nest of the warbling 

 vireo was found suspended as usual in a fork in a small clump 

 of maple, eight feet from the ground. This nest contained 

 four eggs, in which incubation had begun. 



From the date last given until the end of our observations 

 on July 5, nests of this vireo were examined each day, but 

 at this period of the nesting season no more nests were found 

 containing eggs. The foregoing notes will suffice to show the 

 general location of the nest-site and the usual nest com- 

 plement. 



Plate XII. shows an illustration of a typical nest of this 

 species. 



The nest figured in the illustration is an unusually handsome 

 structure, having its exterior covered loosely with fragments of 

 gossamer and bits of soft birch bark, besides showing the 

 shreds of wasp paper woven into the outer wall. The walls are 

 made of fine grass fibers resembling delicate pine shavings. An 

 examination of the illustration will show the manner in which 

 the nest is suspended by its brim. The cavity is two and one- 

 fourth inches and two inches major and minor axes of the 

 brim, the walls curving outM^ard below the rim to give the 

 cavity a sub-spherical form. 



The form of this species found in the Flathead region is 

 described under the subspecific name of Vireo gilvus sivainsonii. 



RED-EYED VIREO, Vireo olivaceus (Linn.) 



This persistent songster is fully as abundant in the Flat- 

 head region as I have found it anywhere in its Mississippi Val- 

 ley range. Everywhere throughout the wooded localities, either 

 in the low willow areas or in the heavily timbered uplands. 



